【国外标准】 Standard Test Methods for Composition of Turpentine and Related Terpene Products by Capillary Gas Chromatography

5.1 Earlier methods for characterizing turpentine and related terpene products were based on physical properties, such as those in Specification D13 and Test Methods D801 and D802, and packed column gas chromatography for the major constituents (for example, α-pinene, β-pinene) as in Test Method D3009. As terpene products became widely used as chemical raw material, the separation and quantitation of compounds present at lower concentrations in the product became more important. The capillary gas chromatographic technique described in these test methods is a rapid and convenient means to perform these analyses.1.1 These test methods describe the determination of the amounts of α-pinene, β-pinene, dipentene, terpene alcohols, and other terpene compounds in turpentine and related terpene products using capillary gas chromatography. The two methods for determining the amount of the individual terpene compounds are the “internal standard” method, which yields absolute values, and the “area percent” method, which yields relative values.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of the standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.NOTE 1: Overall this test method gives excellent repeatability but only moderate reproducibility. This greater than normal differential is a consequence of the variety of gas chromatography (GC) columns and other variables used by participants. These variables, coupled with the complex composition of the test products, enabled some workers to separate peaks that others reported as one peak; thus, this test method gives excellent precision within a given laboratory on a given GC. When laboratory to laboratory comparison have to be made, however, it is essential that the GC operating conditions be defined closely.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.